Board index FlightGear Support Flying

From Europe and want to help test more realistic AAR?

Controlling your aircraft, using the autopilot etc.

From Europe and want to help test more realistic AAR?

Postby onox » Thu Feb 12, 2015 7:28 pm

I have been working on modifying the 707-tt to control the refueling boom and I would like to test the automatic tracking of the boom after making contact with an aircraft. On the ground with a slightly modified B-1B it works, but I want to see how it works in the air. This is just to test the behavior of the boom. I have not worked on the Pilot Director Lights and fuel flow negotiations yet. This is what I want to try:

https://www.youtube.com/watch?feature=p ... uxydM#t=25 (sorry, no youtube tag because it doesn't understand https and #t=)

So are you from Europe and have low latency connection (because otherwise there would be too much lag) and want to help test more realistic aerial refueling? Then it would be great if you could help tonight (maybe 1 hour somewhere between 1900 UTC and perhaps 2300 UTC).

Some requirements:

- It would be best if you're close to mpserver01 or mpserver12
- Can use Mumble for easier communication
- Have drunken enough coffee, no alcohol, and can do (or tries) close formation flying
- It is helpful if you're able to fly the B-1B (you need to grab my modified version)
- You need to be able to download (click a button) and install my modified 707-tt if you want to see the boom moving
- I have tested it with FG git, but 3.2 might work as well for the receiver aircraft
- You do not need to be able to fly the 707

- I cannot guarantee it's going to work because even on localhost you're going to get at least 0.5 seconds of lag, but if you don't try you won't know :)

I would also like to know how to get the autopilot of the 707 to work otherwise I need to trim it with the mouse :(

Some experiment where I used geo.put_model() to see if I could correctly locate the position of the end of the boom:

Image
onox
Retired
 
Posts: 431
Joined: Fri Jun 20, 2014 3:45 pm

Re: From Europe and want to help test more realistic AAR?

Postby Johan G » Thu Feb 12, 2015 7:48 pm

I'm all in. Have not flown the "Bone" for some years (or anything that big for that matter), but I am relatively proficient doing AAR with the Mirage F1.

N.B. I am running 3.0.

Edit: This will be useful (even though they undoubtedly are estimated values): Rockwell B-1 Lancer, Aircraft Performance Database v3.0, EUROCONTROL. :)

Edit2: I will be around China Lake (KNID) practicing. :wink:

Edit3: Probably not too meaningful in this context:
According to ATP-56(B), Part 5, Annex ZE, Appendix 1, fig ZE-1-1, optimal FL/KIAS/M is 210/320/0.70 and I should approach at 350 KIAS (until 1/2 NM away)
According to ATP-56(B), Part 5, Annex ZE, Appendix 5, bank angle in turns while in contact should be limited to 15 deg.
Source: see ATP 3.3.4.2 on in my wiki article. :wink:
Low-level flying — It's all fun and games till someone looses an engine. (Paraphrased from a YouTube video)
Improving the Dassault Mirage F1 (Wiki, Forum, GitLab. Work in slow progress)
Some YouTube videos
Johan G
Moderator
 
Posts: 6629
Joined: Fri Aug 06, 2010 6:33 pm
Location: Sweden
Callsign: SE-JG
IRC name: Johan_G
Version: 2020.3.4
OS: Windows 10, 64 bit

Re: From Europe and want to help test more realistic AAR?

Postby onox » Thu Feb 12, 2015 8:37 pm

I'm there. Can you come online? I can tell you how to modify the F1 a little bit for AAR :)
onox
Retired
 
Posts: 431
Joined: Fri Jun 20, 2014 3:45 pm

Re: From Europe and want to help test more realistic AAR?

Postby onox » Fri Feb 13, 2015 12:50 am

Me and Johan G did some AAR flying. In the air there was just too much lag again, so his plane could only approach up to 100 meters away to avoid sitting in the same cockpit, which is too much, because the distance needs to be less than 1 meter.

After adding some code to the Models/Mirage_F1-model.xml file:

Code: Select all
<multiplay>
    <refuel>
        <offset-x-m>-6.990</offset-x-m>
        <offset-y-m>0.472</offset-y-m>
        <offset-z-m>1.015</offset-z-m>
    </refuel>
</multiplay>


I could get this on the ground:

Image

I just manually move the refueling boom with the mouse and extend it with the scrollwheel and when it gets within 1 meter distance of the fuel contact point, it connects and starts tracking this point. In the screenshot you can see me taxiing away a little bit with the refueling boom automatically extending as much as necessary.

Hopefully jano finally adds his MP anti-lag patch to flighgear.
onox
Retired
 
Posts: 431
Joined: Fri Jun 20, 2014 3:45 pm

Re: From Europe and want to help test more realistic AAR?

Postby Johan G » Fri Feb 13, 2015 9:02 pm

Well, to summarize: All is well on the ground, but in the air it does not seem feasible with the current multiplayer system. :?

Preliminary ground test (worked quite well, though I must say that the boom and probe combination looks a bit weird :wink: ):

Image
Boom and probe refueling?! by Johan G, on Flickr

While in flight it did not work so well. This is my position when onox saw me about 100 meters behind him:

Image
How nice of you to drop in by Johan G, on Flickr

In addition to the lag, I noticed some airspeed variations in the 380-410 KIAS range (assuming he was under autopilot, and disregarding my less then stellar formation skills :wink: ). When taking fuel from an AI tanker it has a rock steady airspeed.
Low-level flying — It's all fun and games till someone looses an engine. (Paraphrased from a YouTube video)
Improving the Dassault Mirage F1 (Wiki, Forum, GitLab. Work in slow progress)
Some YouTube videos
Johan G
Moderator
 
Posts: 6629
Joined: Fri Aug 06, 2010 6:33 pm
Location: Sweden
Callsign: SE-JG
IRC name: Johan_G
Version: 2020.3.4
OS: Windows 10, 64 bit

Re: From Europe and want to help test more realistic AAR?

Postby onox » Fri Feb 13, 2015 9:26 pm

Johan G wrote in Fri Feb 13, 2015 9:02 pm:In addition to the lag, I noticed some airspeed variations in the 380-410 KIAS range (assuming he was under autopilot, and disregarding my less then stellar formation skills :wink: ). When taking fuel from an AI tanker it has a rock steady airspeed.


That is because I was flying manually the whole time since I cannot get the AP to engage. Not in the menu, not with the green panel in front of the pilot, and not with the panel between the pilot and co-pilot :(
onox
Retired
 
Posts: 431
Joined: Fri Jun 20, 2014 3:45 pm

Re: From Europe and want to help test more realistic AAR?

Postby Johan G » Fri Feb 13, 2015 9:46 pm

onox wrote in Fri Feb 13, 2015 9:26 pm:...I cannot get the AP to engage. Not in the menu, not with the green panel in front of the pilot, and not with the panel between the pilot and co-pilot :(

Ouch. :?
Low-level flying — It's all fun and games till someone looses an engine. (Paraphrased from a YouTube video)
Improving the Dassault Mirage F1 (Wiki, Forum, GitLab. Work in slow progress)
Some YouTube videos
Johan G
Moderator
 
Posts: 6629
Joined: Fri Aug 06, 2010 6:33 pm
Location: Sweden
Callsign: SE-JG
IRC name: Johan_G
Version: 2020.3.4
OS: Windows 10, 64 bit

Re: From Europe and want to help test more realistic AAR?

Postby Jabberwocky » Sun Feb 15, 2015 1:03 am

Wel, as ONOX ad me discussed in Mumble some days ago

- the difference of positions due to server lag is in the range of seconds
- which means, the distance in for example feet (meter, yards, miles) depends on your speed
- with a grund speed of 0, ten seconds multiplyed by 0 knots makes still zero, which is why it works on the ground
- with a ground speed of say 300 knots, ten seconds make 0.8333 nm position difference and it doesn't work anymore.

so ... noooo way!
Jabberwocky
Retired
 
Posts: 1316
Joined: Sat Mar 22, 2014 8:36 pm
Callsign: JWOCKY
Version: 3.0.0
OS: Ubuntu 14.04

Re: From Europe and want to help test more realistic AAR?

Postby Johan G » Sun Feb 15, 2015 10:48 am

That is what I was afraid of.
Low-level flying — It's all fun and games till someone looses an engine. (Paraphrased from a YouTube video)
Improving the Dassault Mirage F1 (Wiki, Forum, GitLab. Work in slow progress)
Some YouTube videos
Johan G
Moderator
 
Posts: 6629
Joined: Fri Aug 06, 2010 6:33 pm
Location: Sweden
Callsign: SE-JG
IRC name: Johan_G
Version: 2020.3.4
OS: Windows 10, 64 bit

Re: From Europe and want to help test more realistic AAR?

Postby onox » Sun Feb 15, 2015 4:39 pm

Jabberwocky wrote in Sun Feb 15, 2015 1:03 am:so ... noooo way!


Why are you always so negative? You always see only insurmountable obstacles instead of challenges.

The position error was more something like 0.083 nm instead of 0.83. The MP lag prediction patch has not been merged to flightgear yet. Also, the MP system is slow anyway. Try to run 2 fgfs instances on the same computer connected to each other. You'll see a delay of at least 0.3 seconds when you move the refueling boom. This delay should be something very close to 0.0 seconds. Furthermore, this work can be used for the AI tankers or for an AC-130 gunship for example.
onox
Retired
 
Posts: 431
Joined: Fri Jun 20, 2014 3:45 pm

Re: From Europe and want to help test more realistic AAR?

Postby Johan G » Tue Feb 17, 2015 1:26 pm

onox wrote in Sun Feb 15, 2015 4:39 pm:Furthermore, this work can be used for the AI tankers...

Indeed. :)
Low-level flying — It's all fun and games till someone looses an engine. (Paraphrased from a YouTube video)
Improving the Dassault Mirage F1 (Wiki, Forum, GitLab. Work in slow progress)
Some YouTube videos
Johan G
Moderator
 
Posts: 6629
Joined: Fri Aug 06, 2010 6:33 pm
Location: Sweden
Callsign: SE-JG
IRC name: Johan_G
Version: 2020.3.4
OS: Windows 10, 64 bit

Re: From Europe and want to help test more realistic AAR?

Postby D-MKF1 » Tue Feb 24, 2015 10:04 am

Hope you'll find better refueling action solutions.
Johann, did you know, who maintain the 707 now? I saw there was changings in the git version without any information to me. Greating from the lake of constance :)
If there any problems with the AP, you can contact me usually on the Isle of Man as Roadracer Guy ;))
Marc
D-MKF1
 
Posts: 99
Joined: Mon Sep 30, 2013 6:03 pm
Version: Git
OS: GNU/Linux | Mac OS X

Re: From Europe and want to help test more realistic AAR?

Postby Johan G » Tue Feb 24, 2015 5:16 pm

D-MKF1 wrote in Tue Feb 24, 2015 10:04 am:Johann, did you know, who maintain the 707 now? I saw there was changings in the git version without any information to me.

Huh? I had the general idea that changes to the 707 would be forwarded to you before being added to the Lake of Constance 707 and that you or the old maintainer of the 707 then would add them to svn.
Low-level flying — It's all fun and games till someone looses an engine. (Paraphrased from a YouTube video)
Improving the Dassault Mirage F1 (Wiki, Forum, GitLab. Work in slow progress)
Some YouTube videos
Johan G
Moderator
 
Posts: 6629
Joined: Fri Aug 06, 2010 6:33 pm
Location: Sweden
Callsign: SE-JG
IRC name: Johan_G
Version: 2020.3.4
OS: Windows 10, 64 bit

Re: From Europe and want to help test more realistic AAR?

Postby D-MKF1 » Tue Feb 24, 2015 10:07 pm

Lake of Constance thats the name of my playground. The problem for me was always, if I make any changings on the rebuild 707, I have asked Stuart or James for git updating.
Never understand, why I cannot do this directly. But its ok for me now. To much developer in git is perhaps a problem.
I'm playing with the low-level flight objects now, the racebikes. So I can't come amiss to any developer of flightgear.
The bad words about the 707 times ago killed any propulsion to go on with this time-consuming work for me.
But by far the greatest for me is now, seeing every night the 707 going around the world in flightgear.
It is appreciation, isn't it :))

Thank you,
Marc
D-MKF1
 
Posts: 99
Joined: Mon Sep 30, 2013 6:03 pm
Version: Git
OS: GNU/Linux | Mac OS X

Re: From Europe and want to help test more realistic AAR?

Postby rominet » Sun Mar 15, 2015 10:51 am

Hello,

onox wrote in Fri Feb 13, 2015 9:26 pm:That is because I was flying manually the whole time since I cannot get the AP to engage. Not in the menu, not with the green panel in front of the pilot, and not with the panel between the pilot and co-pilot :(


As I tried to explain yesterday, the 707 autopilot works fine once the correct hemisphere + latitude has been set and the MAG/DG switch put into DG mode. cf. the screenshot from D-MKF1 at http://forum.flightgear.org/viewtopic.php?f=4&t=21349&p=219390#p219801.

You may set the autopilot mode with the buttons in front and a bit to the right of the pilot (AP, HDG, IAS, VS, ALT, NAV, APPR and GPS from memory). Using the mouse wheel:
  • on the airspeed indicator, you can change the target IAS (cf. the white and red needle);
  • on the HSI lower right button, you can change the target heading;
  • on the vertical speed indicator, you can change the target rate of climb/descent.

This autopilot may not be quite as convenient as that of the 777 (most notably, no way to set a target altitude in VS mode, AFAIK), but it works well, even for ILS approaches (with glide slope).

Notes:
  • I don't use the autopilot panel below between the pilot and copilot;
  • I wonder if the DG in the famous MAG/DG button stands for "directional gyro". If someone knowledgeable could confirm...
rominet
 
Posts: 605
Joined: Sat Nov 01, 2014 2:33 pm
Callsign: F-KATS
Version: Git next
OS: Debian GNU/Linux

Next

Return to Flying

Who is online

Users browsing this forum: No registered users and 5 guests